Infant mortality means the death of a child less than one year of age

Read the following statements
(a) Infant mortality means the death of a child less than one year of age.
(b) Infant mortality is the number of deaths of children under one year of age per 1000 live
births.
(c) Poverty of the family is the only factor, that contributes to infant mortality.
Which of the above statements is/are correct ?
(1) (a) and (c)
(2) (b) and (c)
(3) (a) and (b)
(4) (a), (b) and (c)